Add missing_const_for_fn clippy lint (#8498)

crates/blockchain-tree/src/block_buffer.rs

@@ -47,7 +47,7 @@ impl BlockBuffer {
     }
 
     /// Return reference to buffered blocks
-    pub fn blocks(&self) -> &HashMap<BlockHash, SealedBlockWithSenders> {
+    pub const fn blocks(&self) -> &HashMap<BlockHash, SealedBlockWithSenders> {
         &self.blocks
     }
 

crates/blockchain-tree/src/block_indices.rs

@@ -58,12 +58,12 @@ impl BlockIndices {
     }
 
     /// Return fork to child indices
-    pub fn fork_to_child(&self) -> &HashMap<BlockHash, LinkedHashSet<BlockHash>> {
+    pub const fn fork_to_child(&self) -> &HashMap<BlockHash, LinkedHashSet<BlockHash>> {
         &self.fork_to_child
     }
 
     /// Return block to chain id
-    pub fn blocks_to_chain(&self) -> &HashMap<BlockHash, BlockchainId> {
+    pub const fn blocks_to_chain(&self) -> &HashMap<BlockHash, BlockchainId> {
         &self.blocks_to_chain
     }
 
@@ -94,7 +94,7 @@ impl BlockIndices {
     }
 
     /// Last finalized block
-    pub fn last_finalized_block(&self) -> BlockNumber {
+    pub const fn last_finalized_block(&self) -> BlockNumber {
         self.last_finalized_block
     }
 
@@ -366,7 +366,7 @@ impl BlockIndices {
 
     /// Canonical chain needed for execution of EVM. It should contain last 256 block hashes.
     #[inline]
-    pub(crate) fn canonical_chain(&self) -> &CanonicalChain {
+    pub(crate) const fn canonical_chain(&self) -> &CanonicalChain {
         &self.canonical_chain
     }
 }

crates/blockchain-tree/src/blockchain_tree.rs

@@ -227,7 +227,7 @@ where
 
     /// Expose internal indices of the BlockchainTree.
     #[inline]
-    pub fn block_indices(&self) -> &BlockIndices {
+    pub const fn block_indices(&self) -> &BlockIndices {
         self.state.block_indices()
     }
 
@@ -1463,7 +1463,7 @@ mod tests {
     }
 
     impl TreeTester {
-        fn with_chain_num(mut self, chain_num: usize) -> Self {
+        const fn with_chain_num(mut self, chain_num: usize) -> Self {
             self.chain_num = Some(chain_num);
             self
         }

crates/blockchain-tree/src/canonical_chain.rs

@@ -58,7 +58,7 @@ impl CanonicalChain {
     }
 
     #[inline]
-    pub(crate) fn inner(&self) -> &BTreeMap<BlockNumber, BlockHash> {
+    pub(crate) const fn inner(&self) -> &BTreeMap<BlockNumber, BlockHash> {
         &self.chain
     }
 

crates/blockchain-tree/src/chain.rs

@@ -53,7 +53,7 @@ impl DerefMut for AppendableChain {
 
 impl AppendableChain {
     /// Create a new appendable chain from a given chain.
-    pub fn new(chain: Chain) -> Self {
+    pub const fn new(chain: Chain) -> Self {
         Self { chain }
     }
 

crates/blockchain-tree/src/config.rs

@@ -57,18 +57,18 @@ impl BlockchainTreeConfig {
     }
 
     /// Return the maximum reorg depth.
-    pub fn max_reorg_depth(&self) -> u64 {
+    pub const fn max_reorg_depth(&self) -> u64 {
         self.max_reorg_depth
     }
 
     /// Return the maximum number of blocks in one chain.
-    pub fn max_blocks_in_chain(&self) -> u64 {
+    pub const fn max_blocks_in_chain(&self) -> u64 {
         self.max_blocks_in_chain
     }
 
     /// Return number of additional canonical block hashes that we need to retain
     /// in order to have enough information for EVM execution.
-    pub fn num_of_additional_canonical_block_hashes(&self) -> u64 {
+    pub const fn num_of_additional_canonical_block_hashes(&self) -> u64 {
         self.num_of_additional_canonical_block_hashes
     }
 
@@ -84,7 +84,7 @@ impl BlockchainTreeConfig {
     }
 
     /// Return max number of unconnected blocks that we are buffering
-    pub fn max_unconnected_blocks(&self) -> u32 {
+    pub const fn max_unconnected_blocks(&self) -> u32 {
         self.max_unconnected_blocks
     }
 }

crates/blockchain-tree/src/metrics.rs

@@ -90,7 +90,7 @@ pub(crate) enum MakeCanonicalAction {
 }
 
 impl MakeCanonicalAction {
-    fn as_str(&self) -> &'static str {
+    const fn as_str(&self) -> &'static str {
         match self {
             Self::CloneOldBlocks => "clone old blocks",
             Self::FindCanonicalHeader => "find canonical header",

crates/blockchain-tree/src/state.rs

@@ -49,7 +49,7 @@ impl TreeState {
 
     /// Expose internal indices of the BlockchainTree.
     #[inline]
-    pub(crate) fn block_indices(&self) -> &BlockIndices {
+    pub(crate) const fn block_indices(&self) -> &BlockIndices {
         &self.block_indices
     }